Work involving technical safety equipment may only be carried out by proven specialists that have been briefed on the specific working conditions (VUV 5 & 8).
Hence, there should always someone on site capable of rescuing his coworkers from dangerous situations.
Unfortunately, until recently, there have been huge differences in the content and length of training sessions for technical safety equipment to prevent falling accidents.
30 Minute sessions with 15 participants were not uncommon.
The reasons for this are complex, and may have been due to the conditions of the schooling company, as well as the firm receiving the training.
This website should help to improve the situation by standardizing the training options in the interest of course participants. See rubric: Length of Training
An appropriate training for people with limited experience should last a full work day.